Crankcase (4 or 3 cylinders with cast iron bushing), clutch housing, oil pan, steering column, and so forth are all iconic examples of aluminum die castings. Automobile steering wheel structure, which was originally built of aluminum (in iron mold frame), is now predominantly injected with integrated magnesium to decrease weight and moment of inertia. Gearbox forks made of die-cast brass have a new market water body (copper cage rotor, antibacterial alloy parts in the medical industry). Compared with aluminum alloy, zinc alloy market is more varied, utilized for automobile industry, electronic products (hood, card fixing), luxury goods (perfume bottle cap, etc.), sports or medicinal. Finally, fishing, radiation protection, and counterbalance are all possible applications for lead alloy. Here, we are going to talk about background information about die casting.
a variety of machinery (cold chamber, hot chamber, etc.)
According to the changed alloy, cold chamber machine technology or hot chamber machine technology is applied. The two methods are distinct in the degree of holding furnace. Therefore, in the cold chamber molding, the liquid metal is pulled out by the automated ladle (or metering furnace), then poured into the metal container, and lastly injected by the horizontal injection piston. A vertical injection piston injects metal into the mold via a gooseneck and injection nozzle in hot chamber technology, which heats the injection system to 400 degrees Celsius. Zinc and lead alloys are the only metals eligible for this process (which are less corrosive than aluminum in terms of metal elements),
There is also the so-called "multi slider" hot chamber machine, which injects on the splitting surface. These machines (dynacast, techmire) have extremely high productivity and are specifically used for injecting very tiny components (tens of grams) of zinc, lead or magnesium alloys. Depending on the model, the machine contains two or four movable blocks on which the mold blocks are mounted. The technique is special, and the die is incompatible with the typical hot chamber die casting equipment.
Part quality control
The operator watching the machine does a complete visual inspection of the parts to look for any defects (recasting, faults, cracks). Internal faults that do not match component standards (mostly pores and shrinkage traces) are found by radiographic examination when parts are periodically removed from each team (the frequency is dependent on the criticality of the product). Air and water tightness may be evaluated manually or automatically after processing in certain circumstances, either by sampling or by checking the air and water tightness after processing. The leaking component might be the object of the impregnation procedure, in which the resin infiltrates the existing pores to fill them. As a result, following the impregnation process, it is possible to retrieve certain pieces. In order to avoid having to examine the pieces independently, individuals are increasingly striving to check the production parameters as fully as possible. Therefore, at certain sites, the machine checks the primary injection parameters in each cycle, so if one of the monitoring parameters exceeds the min max control interval, the machine may reject the parts in real time. Then the discarded components are either rejected or 100 percent NDT examined. The machine monitors the primary injection parameters in each cycle, so if one of the monitoring parameters exceeds the minimum maximum control interval, the machine may reject the components in real time. A last step involves rejecting or NDT inspecting the deleted components. When one of the primary injection parameters is found to be less than the minimum maximum control interval, the machine may immediately stop the cycle and discard any remaining pieces. The deleted components are then either rejected or 100 percent NDT examined
Brief background information about die casting
Large-scale mass manufacture of lead tin fonts (previously created separately and manually) about 1850 was essential for the main growth of the printing press and played an important role in the creation of a first manual injection machine devoted to the marlet. Then die casting was employed for the first time in the bicycle and phonograph business in the United States. It should be remembered that Charles Babbage (UK) created tiny precision components (lead, antimony, tin and zinc) for his mechanical computer project in 1868. Then, in 1908, Hermann Doehler established the Brooklyn, New York-based doehler die casting firm and devoted himself to the advancement of technology (molds, machines, etc.). Military uses during World War I further taxed the foundry's resources (grenades, rockets...). In those days, the composition of zinc alloy was not standardized due to wide variations in the alloy across different workshops. The growth of American vehicles after World War II and the extremely popular "zinc chromium" design at that time stimulated the large-scale manufacturing of zinc foundries.
Aluminum cold chamber devices were invented considerably later and were not marketed until the 1930s. Josef Polak of the Czech Republic was one of Europe's pioneers in using vertical piston cold chamber machinery (some still in use). Being based in Eastern Europe. Then, with the mechanization and eventual automation of the building site (ladle and automated poeyeur,...) Until today's machines, the horizontal injection of aluminum, simpler, has become prevalent. Die casting was an early target for robotics since Union Inc. produced the first industrial robot for it.
Pressure-casting-produced alloy
Die casting has so far relied most heavily on recycled aluminum alloy. Since Alsi9cu3 (FE) is the most common alloy in the world and is known by many various names (such as A380 in North America and adc10 in Japan), its chemical composition is remarkably similar to that of Alsi9cu3 (FE) (or 46000 according to European standard EN 1706). AlSi12Cu, alsi10mg or less, super silicon alsi17cu4 was then employed in the alloy alsi12 (eutectic). Low iron ductile alloys (of the Silafont type) are now available for the production of components with high mechanical qualities (with or without heat treatment).
Commonly known as simply "zinc alloy," the most common types of zinc alloy are alloys 3 and 5, each of which contains varying amounts of copper. In order to get stronger heat resistance, zinc alloys (ZA8, ZA12 and ZA27) with increased aluminum content (8 percent , 12 percent and 27 percent , respectively) may be utilized. Due to the high heat conductivity of copper, 60/40 brass grade (cuzn40) and new antibacterial grade copper are often injected into copper alloys. Magnesium was changed into a pressure foundry (hot chamber for small components and cold chamber for big parts) (hot chamber for small parts and cold chamber for large parts). There is a difference between AZ91D (the most prevalent) and AM50 and AM60 with increased elongation. Finally, lead alloys (soft lead, lead tin or lead antimony alloys) are injected.
Future evolution of die casting
In order to fulfill the increasing production demands of the automobile industry, die casting has become extensively automated and robotic. Many technologies evolved from die casting (indirect squeeze casting, thixotropic casting, rheo casting, core based on molten salt, closed metal foam such as aluminum and zinc alloy) have been created, but no substantial advance has been achieved in technological maturity (TRL) or mother technology. The injection molding machine's peripheral equipment, such as the quantitative oven, coating robot, mold cooling system (jet cooling), vacuum system, blower cooling components, and degassing rotor, has also been doubled to improve process control. As we said before, additional alloys (ductile alloys, particular zinc alloys) have also been included, offering the design office more alternatives.
Finally, for the manufacture of high value-added car components (engine block), several die-casting companies have introduced shot blasting machines and machining centers, which may minimize the number of personnel managing the production line and restrict the flow of parts in the plant. A quality control system (tomography type) and digital twins of each machine are possible in the future, allowing for better management of manufacturing parameters (cycle time, coating, hot die, etc.) to reduce non-quality and better predict shutdowns (main shaft replacement, etc.) and preventive maintenance to be performed. In the future, die casting may use a version of the 4.0 factory.